Furnace Data

In order to give definite information concerning furnaces, fuels
etc., the following data is quoted from a paper by Seth A. Moulton
and W. H. Lyman before the Steel Heat Treaters Society in September,
1920.

This considers a factory producing 30,000 lb. of automobile gears
per 24 hr. The transmission gears will be of high-carbon steel and
the differential of low-carbon steel, carburized. The heat-treating
equipment required is:

All of the forging blanks are annealed before machining, about
three-quarters of the machined gears and parts are carburized,
all the carburized gears are given a double treatment for core and
case, all gears and parts are hardened and all parts are drawn.

The possible sources of heat supply and their values are as follows:--

For the heat treatment specified only comparatively low temperatures
are required. No difficulty will be experienced in attaining the
desired maximum temperature of 1,800 deg.F. with any of the heating
medium above enumerated; but it should be noted that the producer
gas with a B.t.u. content of 170 per cubic foot and the electric
current would require specially designed furnaces to obtain higher
temperatures than 1800 deg.F.